66668749 has 8 divisors (see below), whose sum is σ = 76536320. Its totient is φ = 56887056.

The previous prime is 66668731. The next prime is 66668803. The reversal of 66668749 is 94786666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66668749 - 2⁵ = 66668717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66668696 and 66668705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66668449) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19794 + ... + 22915.

It is an arithmetic number, because the mean of its divisors is an integer number (9567040).

Almost surely, 2^66668749 is an apocalyptic number.

It is an amenable number.

66668749 is a deficient number, since it is larger than the sum of its proper divisors (9867571).

66668749 is a wasteful number, since it uses less digits than its factorization.

66668749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42939.

The product of its digits is 2612736, while the sum is 52.

The square root of 66668749 is about 8165.0933246351. The cubic root of 66668749 is about 405.4843547183.

The spelling of 66668749 in words is "sixty-six million, six hundred sixty-eight thousand, seven hundred forty-nine".